液相色谱法同时测定豇豆中吡虫啉和啶虫脒残留

摘要

The maximum absorption wavelength of imidacloprid and nitenpyram detected by UV spectrophotometer were 270 nm and 246 nm.To get optimum retention time and separation , the mobile phase should be acetonitrile and water ( V/V, 3∶7 ) .Standard curves of two pesticides were developed , which fit a linear regression ranging from 0.05 to 5 μg· mL-1 .After extracted by homogenate with acetonitrile and purified by C 18 SPE column, the recovery rates of the two pesticides were 75%~110% at the levels of 0.1mg· kg -1 , 0.5mg· kg-1 and 1.5mg· kg -1 with a RSD less than 5%, which showed a good accuracy and stability .This method with a limit of quantification ( LOQ) of 0.01μg· g-1 could be used in the practical detections .%经过紫外扫描确定吡虫啉和啶虫脒的最大紫外吸收波长分别为270和246 nm，通过改变其比例优化出峰时间和分离度，确定V（乙腈）∶V（水）＝3∶7为流动相，建立了两种农药的标准曲线，结果表明在0.05～5μg· mL-1范围内线性关系均良好。进行样品加标回收实验，用乙腈提取，C18固相萃取柱净化，上述条件进行下分析，0.1，0.5，1.5 mg· kg-1三个加标浓度回收率均在75％～110％，变异系数＜5％，准确性和稳定性都较好，方法最低定量限0.01μg· g-1，完全可以用于实际样品的检测。